Users who are troubleshooting scenarios where the AppDynamics *Standalone Machine Agent is not reporting metrics as expected will find causes and solutions here. The following solutions apply to versions 4.4 and higher.
If both an App Server Agent and the Machine Agent are unzipped into the same directory, important files will be overwritten, such as the
When unzipping the App Agent or Machine Agent zip files, make sure to use different directories.
Both the App Server Agent and the Machine Agent use the Java API to get the host ID. The results from the API can be inconsistent and the same JVM can sometimes return a different value for the same machine each time the Machine Agent is restarted.
When the host ID is then registered with the Controller the app server agent and the machine agent can be assigned different host IDs even though they are running on the same machine.
Reset the hostname for the Machine Agent by running the agent with the
-Dappdynamics.agent.uniqueHostId JVM parameter. Set the host ID to be the same as the one the App Server Agent is using.
If the following error is seen in the Machine Agent log file, the cause is hostname resolution, which affects Machine Agent startup and registration.
.ERROR XMLConfigManager - Error in Default Host Identifier Resolver resolving host name
java.net.UnknownHostException: log-aggregate01: log-aggregate01
1. Change permissions on the Machine Agent installation folder for the user ID that the Machine Agent was started under
chmod -R 777 <machine-agent-install
2. Restart the Machine Agent and verify that the zero values are no longer being reported.
3. If restarting does not help, disable Sigar Hardware monitoring located in the
monitor.xmlfile (located at:
<machine-agent-install>/monitors/JavaHardwareMonitor/*), change the enabled property to false.
<enabled>true</enabled> ---> change this to false –> <enabled>false</enabled>
4. Enable OS-specific hardware monitoring found in the
<enabled>false</enabled> ---> change this to true –> <enabled>true</enabled>
5. Restart the Machine Agent and verify that the zero values are no longer being reported.
*As of 2020, the term "Standalone Machine Agent" has been discontinued in favor of simply "Machine Agent.